“This is the proudest moment of my life,” Samira Salim, of Los Angeles, said as she waited for her daughter, Zina, to enter California Memorial Stadium, via its north tunnel, with the rest of the UC Berkeley Class of 2015. Nearby, Becky and Don Talley and Barbara and Steve Little, all of Walnut Creek, were on hand to cheer on their students, Brandon Talley and Renee Little. “It’s been the best ride of my life, watching Renee grow up and succeed,” said Barbara.

These beaming parents were among 21,000 family members and friends at Saturday’s campuswide commencement, featuring a keynote address by tech leader and philanthropist Marc Benioff and moving, personal remarks by top graduating senior, Radhika Kannan. (Text continues below photo slideshow.)

“It’s not winning awards or accolades that’s important, but the values of this university … that took root here in the ’60s” — values of “disruption, change, advocacy for equal rights, giving back,” Benioff, chair and CEO of Salesforce, told the graduating class.

Citing his and his firm’s strong public stand against a recent Indiana measure he said gave businesses legal cover to discriminate against LGBT people, Benioff insisted that “companies can be platforms for change.” But so can each individual, “by using our voice and our values,” he added.

The ceremony marked a formal sendoff for the Class of 2015, which totals some 5,100 undergraduates, more than a quarter of whom are first-generation college grads. Many doctoral and master’s degree recipients took part as well.

Welcoming new grads to a family of 470,000 living Cal alums, Chancellor Nicholas Dirks spoke of the “quest to secure and sustain” the campus’s public mission. “We live in a time,” he said, “when the need to reanimate our commitment to the public sphere … is more important than ever.”

At Berkeley, “you’ve learned that knowledge is power,” Dirks told the crowd. “Now the task is to use this power to address the most significant challenges of our time — including, perhaps most centrally,” he added, to applause, “the importance of making education itself at all levels accessible for all members of our society.”

Dirks presented the president of Ghana’s Ashesi University, Patrick Awuah, with the Elise and Walter A. Haas International Award, given annually to an international alumnus with a distinguished record of service to his or her country.

Awuah, a 1999 alum, said the university he had long dreamed of founding “started here at Berkeley,” while he was earning his MBA at Haas, when faculty and fellow students offered assistance with business planning, curriculum design, architecture concepts and more. All that, he said, “helped create an institution that will touch thousands of lives” on the African continent directly, and millions indirectly. “It’s wonderful when you have a tribe with you on your journey.”

That was a theme strongly echoed by University Medalist Radhika Kannan.

“Cal brings out our competitive side, our independence and the drive to push our boundaries,” she said. But “letting people in,” “reaching out to build support systems” and being there for others are just as important to success and happiness.

A stellar economics and conservation studies major who took fierce pride in not asking others for help, Kannan had to do an about-face, she said, after her mother’s sudden death during her junior year. When she reached out for help in her hour of grief, faculty, staff and students responded in “touching and unexpected ways,” she recalled.

“I am not ashamed to admit that I am afraid for the future,” said Kannan. “But Cal has taught me how important it is to have people that stand by you when things don’t go according to plan.” To meet the global challenges ahead – as well as life’s curveballs – resilience and personal support systems will be essential, she said.

The speakers’ various appeals that grads work for the greater good were not lost on the new graduates, many of whom have public-minded aspirations.

Samira Salim’s daughter, Zina Ahmed, a biology and public health major, is interested in breast cancer research and hopes to go into medicine, according to her parents.

Ruth Ash, 55, who enrolled at Berkeley as an undergrad after raising eight brothers and sisters, called it “very exciting and humbling that Berkeley helped me to achieve my dream.” Her next goal, she said, is a master’s degree in educational development.

“I will be helpful and useful, especially for my country,” offered Indonesian-born business major Debeasinta Budiman.

Nearby, business and math major Subhashree Rengarajan checked the latest tally for the senior gift to Berkeley. As of Saturday morning, she reported, the Class of 2015 had donated $90,684.29 for departments and programs at Berkeley, their new alma mater.